DIRECT TORQUE CONTROL OF PMSM USING PI CONTROLLERS AND SVPWM FOR TORQUE RIPPLE REDUCTION

Abstract

This thesis investigates and compares the modelling, control mechanisms, and performance outcomes of FOC and PI-SVPWM-based DTC techniques for a PMSM drive system. The increasing demand for efficient control strategies in high-performance electric drive applications can offer fast dynamic response, better steady-state performance and reduced torque ripple. In this work, the mathematical modelling of PMSM is developed using abc and d-q reference frame transformations. An analysis of traditional DTC is conducted to identify key drawbacks, particularly its variable switching frequency and elevated ripples in both flux and torque. The proposed PI-SVPWM-based DTC method and FOC technique are implemented in MATLAB/Simulink environment under similar operating conditions for fair performance evaluation. The simulation results are analyzed analysis between FOC and proposed DTC technique is also carried out to evaluate their dynamic and steady-state performance.in terms of speed, electromagnetic torque and transient characteristics. The obtained results show that, in comparison to conventional DTC, the suggested PI-SVPWM-based DTC technique offers better steady-state performance. The FOC technique offers smooth current control and stable operation. Therefore, the proposed control strategy can be considered an effective solution for high-performance PMSM drive applications.